Pancreas and Liver Flashcards
how is chyme rendered isotonic
water is drawn into the hypertonic lumen of the duodenum
why is chyme not diluted in the stomach
the stomach is impermeable to water
what 2 hormones does the duodenum release
CCK and secretin
what does CCK do
gallbladder contraction
relaxation of the sphincter of Oddi
production of pancreatic enzymes
what cells in the pancreas produce the pancreatic enzymes
acini cells
what does secretin do
cause the production of aqueous bicarbonate
what cells in the pancreas respond to secretin
duct cells
which nervous system stimulate pancreatic secretion
parasympathetic NS
what enzymes are produced by the pancreas
amylase, lipase, inactive proteases
why are the proteases produced by the pancreas inactive
so that they don’t cause self digestion
what is the name of the duct when the common bile duct and pancreatic duct join
ampulla of Vater
what happens in pancreatitis
there is a blockage of the pancreatic duct, so pancreatic secretions are remaining the the pancreas - this causes the proteases to then start digesting the pancreas itself
what may cause pancreatitis
gall stones
what is bile made up of
bile acids, bile pigments and alkaline solutions
what is the role of bile
to emulsify fats into smaller droplets os that it is easier for lipases to digest them
what are bile salts
conjugation of 2 bile acids
why must bile acids conjugate
as they can’t emulsify fats on their own well but they can as bile salts
what produce bile acids
hepatocytes secrete them into the canaliculi
what stimulates the production of the alkaline fluid in bile
secretin
what is steatorrhoea
where there is lipids being lost in the faeces
what causes steatorrhoea (2)
less pancreatic lipase secretion
less bile acid production
what happens to digested lipids
they are surrounded by bile salts to form micelles - these are taken to the enterocytes where they diffuse into the cell
in the cells they are rebuilt back up and packaged with apoproteins to form chylomicrons which are transported in the lymphatics
what happens to the bile salts from the micelle once the lipids inside have diffused out
they are reabsorbed in the terminal ilium and delivered back to the liver via the portal vein
in ischaemia what zone of the liver lobule is mostly affected
zone 3 - as this is further away from the portal triad so last to receive blood
which zone of the liver lobule is most likely to be affected by toxic substances
zone 1 -as this is closest to receive the toxic substances from the portal triad
what structures are found in the portal triad
portal vein, hepatic artery and bile duct
